Preparation and Characterization of Polyion Complex Micelles with Phosphobetaine Shells
Preparation and Characterization of Polyion Complex Micelles with Phosphobetaine Shells
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DOI：
10.1021/la401063b
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发表时间：
2013-08-06
期刊：
影响因子：
3.9
通讯作者：
Yusa, Shin-ichi
中科院分区：
文献类型：
--
作者：
Nakai, Keita;Nishiuchi, Midori;Yusa, Shin-ichi
以聚（2-（甲基丙烯酰氧基）乙基磷酰胆碱）-氯化铵（PMPC-b-PMAPTAC）和聚（2-（甲基丙烯酰氧基）乙基磷酰胆碱）-嵌段-聚（2-（丙烯酰胺）-2-甲基丙磺酸钠）（PMPC-b-PAMPS）为大分子链转移剂，通过可逆加成-断裂链转移自由基聚合制备了一对带相反电荷的两嵌段共聚物。亲水性PMPC嵌段中的磷酰胆碱侧基具有阴离子磷酸根和阳离子季氨基，它们在侧基内被中和。因此，PMPC-b-PMAPTAC和PMPC-b-PAMPS的水溶液的混合导致由分离的PIC核和PMPC壳组成的简单核-壳球形聚离子络合物（PIC）胶束的自发形成。PIC胶束的特征在于使用H-1 NMR自旋-自旋（T-2）和自旋-晶格弛豫时间（T-1）扩散有序NMR光谱，静态光散射，动态光散射（DLS），和透射电子显微镜技术。PIC胶束的流体动力学尺寸取决于PMPC-b-PMAPTAC和PMPC-b-PAMPS的混合比;最大尺寸发生在产生化学计量电荷中和的混合比处。随着盐的加入，PIC胶束分解成单聚体。
A pair of oppositely charged diblock copolymers, poly(2-(methacryloyloxy)ethyl phosphorylcholine)-ammonium chloride) (PMPC-b-PMAPTAC) and poly(2(methacryloyloxy)ethyl phosphorylcholine)-block-poly(sodium 2-(acrylamido)-2-methylpropanesulfonate) (PMPC-b-PAMPS), was prepared via reversible addition-fragmentation chain transfer radical polymerization using a PMPC-based macro chain transfer agent. The pendant phosphorylcholine group in the hydrophilic PMPC block has anionic phosphate and cationic quaternary amino groups, which are neutralized within the pendant group. Therefore, the mixing of aqueous solutions of PMPC-b-PMAPTAC and PMPC-b-PAMPS leads to the spontaneous formation of simple core-shell spherical polyion complex (PIC) micelles comprising of a segregated PIC core and PMPC shells. The PIC micelles were characterized using H-1 NMR spin-spin (T-2) and spin-lattice relaxation times (T-1) diffusion-ordered NMR spectroscopy, static light scattering, dynamic light scattering (DLS), and transmission electron microscopy techniques. The hydrodynamic size of the PIC micelle depended on the mixing ratio of PMPC-b-PMAPTAC and PMPC-b-PAMPS; the maximum size occurred at the mixing ratio yielding stoichiometric charge neutralization. The PIC micelles disintegrated to become unimers with the addition of salts.